To add to @JimHowell1970's excellent answer: I designed to top two rows to be completely usable as a synth on its own - VCOs into VCF into VCAs with lots of modulation capabilities. The Grids can be used as the clock source and the Pico DSP can be considered its "output module". I have a Twisted Electrons Crazy8 laying around that I can use as the sequencer.
Curious as to why the variety of VCAs…why wouldn’t you just use one type of VCA multiple times? For example, you have the 3X VCA and then also the Veils quad VCA in the top row…why not just two of the Veils? Is it for different functionality that some have vs others? Different sonics? Looks like the Tallin is also a VCA?
Another interesting tidbit about combining 2 Rackbrutes is that, by default, the lower half mounts "upside down", as can be seen in this video by BoBeats. This means the power supply of the lower Rackbrute will be in the bottom right, which disturbed me. However, by unscrewing the wooden side panels it's possible to "flip" the internal assembly so that the hinge can be mounted on the other side, making the two Rackbrutes in the same orientation again. Definitely something you'll want to do when getting your second Rackbrute!
-- splendor
That is a great tip to know, thanks! I’m probably a good couple years away from that :) I do have the Arturia mini brute 2 which I was thinking to mount to the 6U…second guessing myself as to whether I maybe should have gotten the 2S instead for the sequencing
JB